Just like humans, cows display sidedness behavior. Maybe you have noticed a cow that always lays down on its right side or is a huge fan of the left side of the milking parlor. Scientifically, this is referred to as laterality.

“The right hemisphere of the brain handles fear and anxiety; the left hemisphere processes positive emotions and longer-term memories,” shared Rick Grant in a recent Miner Institute Farm Report.

This correlation between behavior and the emotional state of cows led Australian researchers to conduct a study forcing cows to choose between their right and left sides.

In the study, a person that was foreign to the cows stood in the middle of a 14-foot wide exit lane. As cows exited the parlor, they had to choose between walking to the left or right of the person.

“If a cow passed the novel person on the right side, viewing them with their left eye, which is connected to the right brain, that indicated that the cow was more susceptible to stress and anxiety based on known biology,” explained Grant.

Those cows were more likely to behave anxiously, raise or tuck their tails as they passed, walk more slowly, and pass in a single file line without turning to look at the person. The researchers determined that this group of cows was also more likely to defecate and be higher producing cows.

Cows that passed on the left appeared more comfortable passing in pairs rather than one at a time and looking at the person as they passed.

Grant suggested that these behaviors have been consistent and repeatable, but there are still many questions to answer. What maybe most pressing is why high-producing cows would tend to display more anxious behavior? Additionally, are some environmental stressors more telling than others? Can this behavior be monitored or managed to reduce stress?

Research and time may tell us if we should care if our cows are “lefties” or not.